Study On The Flame Retardant Properties Of Carrageenan Fiber And Its Composite

Carrageenan is a linear polysaccharide extracted from natural red algae,composed of1,3-linked β-D-galactopyranose and 1,4-linked α-D-galactopyranose,1,4-linked 3,6-endether-α-D-galactopyranose composition.During the preparation of carrageenan fibers,the sulfate groups in the molecular chains of carrageenan can combine with metal ions to form a stable gel structure.Under the current situation that non-renewable resources such as petroleum are becoming increasingly depleted,seaweed fibers prepared from carrageenan have attracted more and more attention because of their good renewability,biodegradability,and biocompatibility.In this study,we conducted a more in-depth analysis of the flame retardant and mechanical properties of carrageenan fibers,and explored the application fields of carrageenan fibers.First,carrageenan fibers(labeled as CAF-K,Mg,CAF-K,Ca and CAF-K,Cu)of three types of cross-linked divalent metal ions were prepared by wet spinning.The mechanical strength and flame retardancy of fibers were analyzed using a single fiber tester,X-ray photoelectron spectroscopy(XPS),limiting oxygen index(LOI),vertical burning test(VF)and cone calorimetry,scanning electron microscopy(SEM).The results showed that both the mechanical strength and flame retardancy of carrageenan fibers were affected by the O1 s binding energy,and the mechanical strength is positively correlated with the S-O binding energy.In terms of flame retardancy,the binding energy significantly affected the smoldering process of carrageenan fibers.In order to explore the application of carrageenan fibers in medical dressings,carrageenan fibers cross-linked with zinc ions(CAF-K,Zn)were prepared.The experimental results showed that CAF-K,Zn had good appearance and mechanical properties,the maximum breaking force is 8.09 c N,and the breaking strength is 1.12 c N/dtex,CAF-K,Zn has excellent liquid absorption performance for normal saline and solution A,reaching 21.11 g/g and 22.82 g/g respectively.The antibacterial performance test showed that CAF-K,Zn had obvious antibacterial zones around them,indicating good antibacterial effects on Staphylococcus aureus and Escherichia coli performance.In order to explore the application field of carrageenan fiber and explore the flame retardant properties of carrageenan fiber material prepared by metal ion pre-crosslinking,carrageenan fiber was prepared into carrageenan fiber paper(Al/CAP,Fe/CAP)by Rapid K?then method.Through LOI,VF,SEM and other tests to study its flame retardant mechanism and flame retardant performance.The results showed that Al/CAP exhibited good flame retardancy and thermal stability,and its LOI value reached 52%.There is almost no smoldering phenomenon.Fe/CAP is not as flame retardant as Al/CAP with an LOI of32%,but Fe/CAP has lower total smoke generation(TSP)in cone calorimetry tests.Blending can combine the excellent properties of different types of fibers.In order to explore the flame retardancy of viscose fiber and carrageenan fiber blended materials,Viscose/Carrageenan fibers blended paper(VIF/CAF)was successfully prepared in a green way without any pollution.The thermal degradation performance and flame retardancy of VIF/CAF paper were tested by thermogravimetric analysis(TGA),LOI,flammability test and cone calorimeter test.The results showed that the introduction of carrageenan fibers significantly changed the thermal stability and flame retardancy of VIF/CAF paper.In addition,the introduction of carrageenan fiber significantly improved the mechanical strength of VIF/CAF papers.